Total occlusion guidewire device

ABSTRACT

A guidewire comprising a spreader or at least one centering device which may be used to open occluded vessels or other biological passages, especially chronic total occlusions. The guidewire may be used to either open the lumen or to center a boring device within the lumen, so that the chronic total occlusion can be crossed, and an interventional procedure can then be performed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a guidewire, and more particularly to aguidewire which can cross a vessel which is totally occluded.

2. Discussion of Related Art

Percutaneous transluminal coronary angioplasty (PTCA) and stenting aretherapeutic medical procedures used to increase blood flow through thecoronary arteries and can often be used as alternatives to coronarybypass surgery. In PTCA procedures, the angioplasty balloon is inflatedwithin the stenosed vessel, at the location of an atheroma or plaquedeposit, in order to shear and disrupt the wall components of the vesselto obtain an enlarged lumen. In stenting, an endoluminal prosthesis isimplanted in the vessel to maintain patency following the procedure. Inorder to initiate these procedures, one must first introduce a guidewireinto the lumen of the vessel to serve as a conduit for otherinterventional devices, such as angioplasty balloons and stent deliverysystems. This guidewire must be advanced into a position past thelocation of the atheroma or plaque deposit.

Guidewires should be capable of traversing tortuous pathways within thebody, consisting of bends, loops and branches. For this reason,guidewires need to be flexible, but they should also be sufficientlystiff to serve as a conduit for other devices. In addition, they must betorqueable to facilitate directional changes as they are guided intoposition. Guidewires are typically made of stainless steel, tantalum orother suitable materials, and include a variety of different designs.For example, U.S. Pat. Nos. 3,789,841, 4,545,390 and 4,619,274 discloseguidewires in which the distal segment is tapered for greaterflexibility. The tapered section may be enclosed in a wire coil,typically a platinum coil, which provides increased column strength andtorqueability. Another design is identified in U.S. Pat. No. 5,095,915,where the distal segment is encased in a polymer sleeve with axiallyspaced grooves to provide bending flexibility.

In some cases, a vessel may be totally occluded, and even a guidewirecannot be introduced. This condition is referred to as a chronic totalocclusion. In these cases, the true lumen of the vessel is embedded inthe occlusion and is surrounded by false lumens that have been createdover time. As the clinician attempts to cross the true lumen, the tip ofthe guidewire tends to penetrate the false lumens of the occlusion,which may result in vessel perforation, dissection, or release of plaqueparticles into the bloodstream. Also, as the clinician attempts to crossthe lumen, the tip of the guidewire has a natural tendency to bedirected toward the side of the occlusion rather than the center due tothe configuration of the occlusion, which can also result in vesselperforation, dissection and inability to cross the occlusion. There iscurrently no effective interventional treatment method for such cases.

The prior art makes reference to the use of alloys such as Nitinol(Ni—Ti alloy), which have shape memory and/or superelasticcharacteristics, in medical devices which are designed to be insertedinto a patient's body. The shape memory characteristics allow thedevices to be deformed to facilitate their insertion into a body lumenor cavity, and then heated within the body so that the device returns toits original shape. Superelastic characteristics, on the other hand,generally allow the metal to be deformed and restrained in the deformedcondition to facilitate the insertion of the medical device containingthe metal into a patient's body, with such deformation causing the phasetransformation. Once within the body lumen, the restraint on thesuperelastic member can be removed, thereby reducing the stress thereinso that the superelastic member can return to its original un-deformedshape by the transformation back to the original phase.

Alloys having shape memory/superelastic characteristics generally haveat least two phases. These phases are a martensite phase, which has arelatively low tensile strength and which is stable at relatively lowtemperatures, and an austenite phase, which has a relatively hightensile strength and which is stable at temperatures higher than themartensite phase.

Shape memory characteristics are imparted to the alloy by heating themetal to a temperature above which the transformation from themartensite phase to the austenite phase is complete, i.e. a temperatureabove which the austenite phase is stable (the Af temperature). Theshape of the metal during this heat treatment is the shape “remembered.”The heat-treated metal is cooled to a temperature at which themartensite phase is stable, causing the austenite phase to transform tothe martensite phase. The metal in the martensite phase is thenplastically deformed, e.g. to facilitate the entry thereof into apatient's body. Subsequent heating of the deformed martensite phase to atemperature above the martensite to austenite transformation temperaturecauses the deformed martensite phase to transform to the austenite phaseand during this phase transformation the metal reverts back to itsoriginal shape if unrestrained. If restrained, the metal will remainmartensitic until the restraint is removed.

Methods of using the shape memory characteristics of these alloys inmedical devices intended to be placed within a patient's body presentoperational difficulties. For example, with shape memory alloys having astable martensite temperature below body temperature, it is frequentlydifficult to maintain the temperature of the medical device containingsuch an alloy sufficiently below body temperature to prevent thetransformation of the martensite phase to the austenite phase when thedevice was being inserted into a patient's body. With intravasculardevices formed of shape memory alloys having martensite-to-austenitetransformation temperatures well above body temperature, the devices canbe introduced into a patient's body with little or no problem, but theyare typically heated to the martensite-to-austenite transformationtemperature which is frequently high enough to cause potential tissuedamage and patient discomfort.

When stress is applied to a specimen of a metal, such as Nitinol,exhibiting superelastic characteristics at a temperature above which theaustenite is stable (i.e. the temperature at which the transformation ofmartensite phase to the austenite phase is complete), the specimendeforms elastically until it reaches a particular stress level where thealloy then undergoes a stress-induced phase transformation from theaustenite phase to the martensite phase. As the phase transformationproceeds, the alloy undergoes significant increases in strain but withlittle or no corresponding increases in stress. The strain increaseswhile the stress remains essentially constant until the transformationof the austenite phase to the martensite phase is complete. Thereafter,further increases in stress are necessary to cause further deformation.The martensitic metal first deforms elastically upon the application ofadditional stress and then plastically with permanent residualdeformation.

If the load on the specimen is removed before any permanent deformationhas occurred, the martensitic specimen will elastically recover andtransform back to the austenite phase. The reduction in stress firstcauses a decrease in strain. As stress reduction reaches the level atwhich the martensite phase transforms back into the austenite phase, thestress level in the specimen will remain essentially constant (butsubstantially less than the constant stress level at which the austenitetransforms to the martensite) until the transformation back to theaustenite phase is complete, i.e. there is significant recovery instrain with only negligible corresponding stress reduction. After thetransformation back to austenite is complete, further stress reductionresults in elastic strain reduction. This ability to incur significantstrain at relatively constant stress upon the application of a load andto recover from the deformation upon the removal of the load is commonlyreferred to as superelasticity or pseudoelasticity. It is this propertyof the material which makes it useful in manufacturing tube-cutself-expanding stents. The prior art makes reference to the use of metalalloys having superelastic characteristics in medical devices which areintended to be inserted or otherwise used within a patient's body. Seefor example, U.S. Pat. No. 4,665,905 (Jervis).

Some guidewire designs have recommended the use of superelastic alloys.For example, U.S. Pat. No. 4,925,445 discloses a guidewire where thedistal segment, and at least one portion of the proximal segment, ismade from a superelastic alloy like Nitinol, where the transformationtemperature from austensite to martensite occurs at 10° C. or below.Also, U.S. Pat. No. 4,984,581 discloses a guidewire having a core ofshape memory alloy, where the shape memory properties of the alloyprovide both tip-deflection and rotational movement in response to acontrolled thermal stimulus. Other guidewires made from superelasticNitinol alloys include U.S. Pat. Nos. 4,969,890, 4,991,602, 5,069,226,and 5,171,383.

However, the prior art has yet to disclose any guidewires made fromself-expanding, shape-memory alloys which may be used to address theclinical problem of chronic total occlusions.

SUMMARY OF THE INVENTION

The present invention provides for a guidewire which may be used tocross chronic total occlusions, and which overcomes many of thedisadvantages associated with the prior art devices, as brieflydescribed above.

In accordance with one aspect, the present invention is directed to aguidewire comprising a flexible wire having an outer diameter and aninner diameter, a spreader attached to the distal end of the flexiblewire, having a smaller first diameter for insertion into a vessel, and alarger second diameter for expanding the lumen of the vessel, and a corewire inserted into the flexible wire and the spreader, which is used tocontrol the diameter of the spreader. The spreader is then advancedthough the chronic total occlusion in a ratcheting fashion to open thevessel.

In accordance with another aspect, the present invention is directed toa guidewire comprising a flexible wire having an outer diameter and aninner diameter, a spreader attached to the distal end of the flexiblewire, having a smaller first diameter for insertion into a vessel, and alarger second diameter for expanding the lumen of the vessel, and asheath inserted over the flexible wire and the spreader, which is usedto control the diameter of the spreader. The spreader is then advancedthough the chronic total occlusion in a ratcheting fashion to open thevessel.

In accordance with another aspect, the present invention is directed toa guidewire comprising a flexible wire having an outer diameter and aninner diameter, at least one centering device attached to the distal endof the flexible wire, having a smaller first diameter for insertion intoa vessel, and a larger second diameter for centering the device in thelumen of the vessel, and a sheath inserted into over the flexible wireand the centering device, which is used to control the diameter of thecentering device. The present invention also comprises a rotatable corewire with a boring tip, which is inserted through the flexible wire andthe centering device or devices, and rotated while in contact with theocclusion, to open the lumen of the vessel.

The advantages of the present invention are that the superelasticcapabilities of Nitinol may be used to either open the lumen or tocenter a boring device within the lumen, so that the chronic totalocclusion may be crossed. Once the occlusion is crossed, additionalinterventional devices such as angioplasty balloons and stents may beadvanced over the guidewire, and may be placed at the site of theocclusion, so that balloon angioplasty, stenting, or otherinterventional procedures may then be performed. As a result, currentlyuntreatable patients, whose only alternative is often bypass surgery,may be treated in a less-invasive fashion through the use of thisdevice.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing and other aspects of the present invention will best beappreciated with reference to the detailed description of the inventionin conjunction with the accompanying drawings, wherein:

FIG. 1 is a simplified, partial cross-sectional view of an exemplaryembodiment of the total occlusion guidewire device, with the spreader inthe closed position, in accordance with the present invention.

FIG. 2 is a view similar to that of FIG. 1 but showing the spreader inthe open position in accordance with the present invention.

FIG. 3 is a simplified, partial cross-sectional view of anotherexemplary embodiment of the total occlusion guidewire device, with thesheath over the centering device in the “as delivered” position, inaccordance with the present invention.

FIG. 4 is an enlarged, simplified, partial cross-sectional view similarto FIG. 3 but showing the total occlusion guidewire device with thesheath retracted, and the centering device in the “as deployed”position, in accordance with the present invention.

FIG. 5 is an enlarged, simplified, partial cross-sectional view of fivedifferent exemplary embodiments of the boring guide tip of the totalocclusion guidewire device, in accordance with the present invention.

FIG. 6 is a simplified, partial, cross-sectional view of anotherexemplary embodiment of the total occlusion guidewire device, withmultiple centering devices, in accordance with the present invention.

FIG. 7 is an enlarged, simplified, partial cross-sectional view of asegment of the spreader or the centering device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The total occlusion guidewire device of the present invention isdesigned to cross a totally occluded vessel. The device comprisesvarious means for opening the true lumen of the vessel, includingspreaders, centering devices and boring guide tips. The spreader issimply positioned in proximity to the occlusion and opened to increasethe diameter of the lumen, in order to advance the guidewire through thelumen. Centering devices with boring guide tips may also be utilized toopen the true lumen of the vessel. Centering devices may be utilized toposition and retain a boring guide tip in the center of the lumen inorder to insure proper positioning, and then the boring guide tip may beutilized to essentially cut through the occlusion if necessary.

While the present invention may be realized in a number of exemplaryembodiments, for ease of explanation, three exemplary embodiments willbe described in detail. Referring to the figures wherein like numeralsindicate the same element throughout the views, there is shown in FIGS.1 and 2, a total occlusion guidewire device 10 made in accordance withthe present invention. The total occlusion guidewire device 10 comprisesa flexible wire 25, a spreader 15, which is permanently or removablyattached to the distal end of the flexible wire 25, and a core wire 20,which is used to control the diameter of the spreader. As illustrated inFIG. 1, the core wire 20 has been inserted into the flexible wire 25 andslidably advanced through the flexible wire 25 and the spreader 15, andis substantially in contact with the distal end of the spreader 15.Therefore, as illustrated in FIG. 1, the spreader 15 has achieved itslongest length and its smallest diameter and is in the closed position.In FIG. 2, the slidable, core wire 20 has been advanced through theflexible wire 25 only, and is substantially in contact with the proximalend of the spreader 15, thereby causing the spreader 15 to achieve itsshortest length and to open up to its largest diameter. The spreader 15may comprise a plurality of longitudinally or circumferentially arrangedstruts extending between the distal portion and the proximal portion ofthe spreader, such that advancing the spreader 15 over the core wire 20frees the struts and allows them to expand to their largest diameter,and advancing the core wire 20 through the spreader 15 aligns the strutsin a flat, closed position. As illustrated in FIG. 7, the spreader 15may alternately comprise a plurality of hingedly connected members 17.The core wire 20 may alternately be permanently attached to the distalend of the spreader 15. The core wire 20 may also alternately have aninner diameter to accommodate another guidewire.

Referring back to FIGS. 1 and 2, the total occlusion guidewire device 10may be made from any number of suitable materials, and is preferablymade from a superelastic alloy such as Nitinol. The core wire 20 and theflexible wire 25 may be coated with any number of lubricious,biocompatible coatings. The spreader 15 may be made from any number ofsuitable materials, and is preferably made from a superelastic alloysuch as Nitinol.

The exemplary embodiment of the total occlusion guidewire device 10, asillustrated in FIGS. 1 and 2, is used to cross a chronic total occlusionby inserting it into the lumen of the occluded vessel, and thenadvancing it through the lumen until the distal end of the device is asclose as possible to the occlusion. Then, the spreader 15 and theflexible wire 25 are advanced over the core wire 20, until the spreader15 is in the open position, and achieves its shortest length and largestdiameter and opens the occlusion. At this point, the core wire 20 isadvanced through the flexible wire 25 and the spreader 15, until thedistal end of the core wire 20 is substantially in contact with thedistal end of the spreader 15, and the spreader 15 has achieved itslongest length and smallest diameter and is in the closed position. Thisprocess is then repeated in a ratcheting fashion until the occlusion isfully opened. Once the occlusion is fully opened, additionalinterventional devices such as angioplasty balloons and stents may beadvanced over the total occlusion guidewire device, and may be placed atthe site of the occlusion, so that balloon angioplasty, stenting, orother interventional procedures may then be performed to complete thetreatment of the patient.

FIGS. 3, 4 and 5 show a second exemplary embodiment of the totalocclusion guidewire device. FIG. 4 shows a total occlusion guidewiredevice 10, which comprises a flexible wire 25, a centering device 40,which is permanently or removably attached to the distal end of theflexible wire 25, a rotatable core wire 50, a boring guide tip 45, whichis permanently or removably attached to the distal end of the rotatablecore wire, and a sheath 30, which is used to control the diameter of thecentering device. As illustrated in FIG. 4, the rotatable core wire 50has been inserted into the flexible wire 25 and slidably advancedthrough the flexible wire 25 and the centering device 40 until theboring guide tip 45 of the rotatable core wire 50 extends beyond thedistal end of the centering device 40. As illustrated in FIG. 4, thecentering device 40 is in the open position and has achieved itsshortest length and largest diameter. As illustrated in FIG. 3, thesheath 30 has been inserted over the flexible wire and has been slidablyadvanced over the flexible wire and the centering device, and issubstantially in contact with the distal end of the centering device 35.Therefore, the centering device is in the closed position and hasachieved its longest length and smallest diameter. The centering device40 may comprise a plurality of longitudinal struts or circumferentialstruts extending between the distal portion and the proximal portion ofthe centering device 40, such that advancing the sheath 30 over thecentering device 40 aligns the struts in a flat, closed position, andretracting the sheath 30 frees the struts and allows them to expand totheir largest diameter. As illustrated in FIG. 7, the centering devicemay alternately comprise a plurality of hingedly connected members 17.As illustrated in FIG. 5, a number of alternate designs for the boringguide tip 45A, 45B, 45C, 45D and 45E are shown, including circular guidetips with metal oxide layers or milled ends, cutting surfaces, andscrew-type configurations. As an alternate to a boring guide tip, adevice providing an energy source, such as laser energy, may be utilizedto penetrate the occlusion.

The total occlusion guidewire device 10 may be made from any number ofsuitable materials, and is preferably made from a superelastic alloysuch as Nitinol. The rotatable core wire 50, the flexible wire 25, andthe sheath 30 may be coated with any number of lubricious, biocompatiblecoatings. The centering device 40 may be made from any number ofsuitable materials, and is preferably made from a superelastic alloysuch as Nitinol.

The exemplary embodiment of the total occlusion guidewire device 10, asillustrated in FIGS. 3, 4 and 5, is used to cross a chronic totalocclusion by inserting it into the lumen of the occluded vessel, andthen advancing it through the lumen until the boring guide tip 45 of therotatable core wire 50 is as close as possible to the occlusion. Then,the sheath 30 is slidably retracted over the centering device 35 untilthe centering device 35 has achieved its shortest length and largestdiameter, and centers the devices within the lumen of the vessel. Then,the boring guide tip 45 and the rotatable core wire 50 are slidablyadvanced through the flexible wire 25 until the boring guide tip 45 issubstantially in contact with the occlusion. Finally, the rotatable corewire 50 and the boring guide tip 45 are rotated and advanced until theocclusion is fully opened. Once the occlusion is fully opened,additional interventional devices such as angioplasty balloons andstents may be advanced over the total occlusion guidewire device 10, andmay be placed at the site of the occlusion, so that balloon angioplasty,stenting, or other interventional procedures may then be performed tocomplete the treatment of the patient.

FIG. 6 illustrates a third exemplary embodiment of the total occlusionguidewire device. As illustrated in FIG. 6, a total occlusion guidewiredevice 10 may comprise two centering devices 40 attached to a flexiblewire 25. As illustrated in FIG. 6, a boring guide tip 45 is attached tothe rotatable core wire that has been inserted into the flexible wire25. Centering devices may be joined by flexible members such aspolymeric tubing or coils, to provide longitudinal flexibility andvessel configuration around bends. Centering devices may also bereplaced with short, concentric balloons which may be pressurizedsimultaneously to center the device.

The total occlusion guidewire device 10 may be made from any number ofsuitable materials, and is preferably made from a superelastic alloysuch as Nitinol.

The exemplary embodiment of the total occlusion guidewire device asillustrated in FIG. 6 functions in the same manner as the exemplaryembodiment of the total occlusion guidewire device as illustrated inFIGS. 3, 4 and 5, and the centering devices 40 provide enhancedcentering capability for the boring guide tip 45. As illustrated in FIG.6, the boring guide tip 45 is substantially in contact with the chronictotal occlusion 60. The boring guide tip 45 is rotated and advanceduntil the occlusion is fully opened. Once the occlusion is fully opened,additional interventional devices such as angioplasty balloons andstents may be advanced over the total occlusion guidewire device 10, andmay be placed at the site of the occlusion 60, so that balloonangioplasty, stenting, or other interventional procedures may then beperformed to complete the treatment of the patient.

Although shown and described are what are believed to be the preferredembodiments, it is apparent that departures from specific designs andmethods described and shown will suggest themselves to those skilled inthe art and may be used without departing from the spirit and scope ofthe invention. The present invention is not restricted to the particularconstructions described and illustrated, but should be constructed tocohere with all modifications that may fall within the scope of theappended claims.

1-30. (canceled)
 31. A guidewire for insertion into a lumen, saidguidewire comprising: a flexible wire having an outer diameter, an innerdiameter, a proximal end and a distal end; a generally solid, rotatablecore wire having an outer diameter, a proximal end and a distal end,with said distal end of said rotatable core wire slidably inserted intosaid proximal end of said flexible wire; a guide tip attached to saiddistal end of said rotatable core wire, wherein said guide tip comprisesa boring surface; a sheath, having an outer diameter and an innerdiameter, a proximal end and a distal end, with said distal end of saidsheath slidably insertable over said proximal end of said flexible wire,and a sheath, having an outer diameter and an inner diameter, a proximalend and a distal end, with said distal end of said sheath slidablyinsertable over said proximal end of said flexible wire; at least onecentering device attached to said distal end of said flexible wire, saidat least one centering device having a proximal end and a distal end, asmaller first diameter for insertion into said lumen, and a secondlarger diameter for centering said flexible wire in said lumen, said atleast one centering device having said smaller first diameter when saidsheath is slidably inserted over said flexible wire and said centeringdevice, until said distal end of said sheath is substantially in contactwith said guide tip, and said at least one centering device having saidlarger second diameter when said sheath is slidably retracted from saidguide tip until said distal end of said sheath is no longer in contactwith said at least one centering device.
 32. The guidewire according toclaim 31, wherein there are a plurality of centering devices.
 33. Theguidewire according to claim 31, wherein said plurality of centeringdevices each have a proximal end and a distal end, a smaller firstdiameter for insertion into said lumen, and a second larger diameter forcentering said flexible wire in said lumen.
 34. The guidewire accordingto claim 31, wherein said flexible wire is made from super-elasticNickel-Titanium alloy.
 35. The guidewire according to claim 31, whereinsaid flexible wire incorporates segments made from a polymeric material.36. The guidewire according to claim 31, wherein said at least onecentering device is made from super-elastic Nickel Titanium alloy. 37.The guidewire according to claim 31, wherein said flexible wire and saidat least one centering device are both made from super-elasticNickel-Titanium alloy.
 38. The guidewire according to claim 31, whereinsaid at least one centering device comprises a proximal portion and adistal portion, and a plurality of longitudinal struts extendingtherebetween.
 39. The guidewire according to claim 31, wherein said atleast one centering device comprises a proximal portion and a distalportion, and a plurality of circumferential struts extending in a spiralpattern therebetween.
 40. The guidewire according to claim 31, whereinsaid at least one centering device comprises a proximal portion and adistal portion, and a plurality of hingedly connected struts extendingtherebetween.
 41. The guidewire according to claim 31, wherein saidsheath is made from a polymeric material.
 42. The guidewire according toclaim 31, wherein said at least one centering device is permanently orremovably attached to said distal end of said flexible wire.
 43. Theguidewire according to claim 31, wherein said boring guide tip ispermanently or removably attached to said distal end of said flexiblewire.
 44. A method for crossing an intravascular occlusion in a lumen,comprising the steps of: (a) inserting a guidewire into said lumen, saidguidewire having a proximal end and a distal end; (b) advancing saidguidewire through said lumen until said intravascular occlusion isreached; (c) placing a spreader, attached to said distal end of saidguidewire, in proximity to said occlusion; (d) slidably advancing saidspreader and said guidewire over a core wire until said spreadersubstantially achieves a larger second diameter and opens saidocclusion; e) slidably advancing said core wire through said guidewireand said spreader until said spreader substantially achieves a smallerfirst diameter; and (f) repeating steps c through e by advancing saidguidewire and said spreader over said core wire and then advancing saidcore wire through said guidewire and said spreader wire until saidocclusion in said lumen is fully opened.
 45. A method for crossing anintravascular occlusion in a lumen, comprising the steps of: (a)inserting a guidewire into said lumen, said guidewire having a proximalend and a distal end; (b) advancing said guidewire through said lumenuntil said intravascular occlusion is reached; (c) placing a spreader,at said distal end of said guidewire, in proximity to said occlusion;(d) slidably retracting a sheath over said spreader until said spreadersubstantially achieves a larger second diameter and opens saidocclusion; (e) slidably advancing said sheath over said spreader untilsaid spreader substantially achieves a smaller first diameter; and (f)repeating steps c through e by placing said spreader as close aspossible to said occlusion, slidably retracting said sheath over saidspreader and then advancing said sheath over said spreader until saidocclusion in said lumen is fully opened.
 46. A method for crossing anintravascular occlusion in a lumen, comprising the steps of: (a)inserting a guidewire into said lumen, said guidewire having a proximalend and a distal end; (b) advancing said guidewire through said lumenuntil said intravascular occlusion is reached; (c) placing a guide tipof a rotatable core wire in proximity to said occlusion; (d) slidablyretracting a sheath over at least one centering device, at said distalend of said guidewire, until said at least one centering devicesubstantially achieves a larger second diameter and centers saidguidewire in said lumen; (e) slidably advancing said rotatable core wirethrough said guidewire until a boring surface of said guide tip of saidrotatable core wire is substantially in contact with said occlusion; and(f) rotating and slidably advancing said rotatable core wire with saidguide tip and said boring surface until said occlusion in said lumen isfully opened.